package com.cxl.parser;

import java.net.HttpURLConnection;
import java.net.URL;

public class URLAvailability {
private static URL url;
private static HttpURLConnection con;
private static int state = -1;

/**
   * 功能：检测当前URL是否可连接或是否有效,
   * 描述：最多连接网络 5 次, 如果 5 次都不成功，视为该地址不可用
   * @param urlStr 指定URL网络地址
   * @return URL
   */
public synchronized URL isConnect(String urlStr) {
   int counts = 0;
   if (urlStr == null || urlStr.length() <= 0) {                       
    return null;                 
   }
   while (counts < 5) {
    try {
     url = new URL(urlStr);
     con = (HttpURLConnection) url.openConnection();
     state = con.getResponseCode();
     System.out.println(counts +"= "+state);
     if (state == 200) {
      System.out.println("URL可用！");
     }
     break;
    }catch (Exception ex) {
     counts++; 
     System.out.println("URL不可用，连接第 "+counts+" 次");
     urlStr = null;
     continue;
    }
   }
   return url;
}
}